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Talk abstracts

St. Louis BEES Fall 2011 Retreat

Oral Presentations

 

Brain evolution triggers increased diversification of electric fishes

Bruce Carlson (Washington University)


Phylogenetic and biogeographic relationships within the endemic subtribe Espeletiinae Cuatrec. (Asteraceae) of the South American páramos: preliminary results

Mauricio Diazgranados1, 2*, Janet C. Barber1 (Saint Louis University)

The primary goal of my dissertation project (in progress) is to understand the patterns and mechanisms of speciation in the páramos, and the consequences of climate change on the geographic distribution of species.  This is being accomplished using the dramatic radiation of the more than 150 species of frailejones (subtribe Espeletiinae, family Asteraceae) of the Andean forest and páramos, which provide a potential model system for investigating these phenomena. The immediate goals of my dissertation project are to: 1) build a digital identification key for the species; 2) reconstruct a robust phylogeny of frailejones using multiple molecular markers; 3) model the geographic distribution of the species to interpret the phylogeny in a geographical context; and 4) estimate potential changes in geographical distribution of species under different scenarios of climate change.

1 Saint Louis University, Department Of Biology, 3507 Laclede Avenue, St. Louis, MO, 63103, USA

2 Missouri Botanical Garden, 4344 Shaw Boulevard, Saint Louis, MO 63110, USA

* Presenting author

 

Phylogeny and Genome Evolution in the Andropogoneae (Poaceae):

Matt Estep (University of Missouri - St. Louis)

The genomics revolution is restructuring our understanding of flowering plant evolution and is refocusing systematists to better understand whole genome duplications influence on phylogenetic history. In an effort to study the influence of polyploidy (i.e. WGD) on the diversification and evolutionary history of grasses, our research focuses on the economically important tribe Andropogoneae. This clade has long been recognized as a group that rapidly diversified over the last 18MYA and contains multiple examples of polyploidy, possibly the result of hybridization between genera. In order to accomplish our goals, a series of 10 low copy nuclear markers were designed, new sequence sampling strategies were employed, and taxonomic sampling was increased. The preliminary results will be presented.

 

Tropicos® beyond taxonomy

Peter M. Jørgensen (Missouri Botanical Garden)
Tropicos® is Missouri Botanical Garden’s database system for plant information. The history, philosophy, and structure of the database will be briefly described. The database has been developed to answer needs by staff and projects in solving floristic research questions. The database is consequently biased towards areas where the garden works, as well as towards specific taxonomic groups. The way synonymy is captured and stored is unique to Tropicos® and has turned out to be extremely useful for a broader audience in taxonomy, biogeography, and ecology. Examples will be provided as to how “computed acceptance” of a name has been used in external projects. As well as examples on solutions to find the correct name for the species present in an ecological study. Because Tropicos® has been designed to solve floristic problems, it handles synonymy and voucher specimens well, and it has in other words the fundamental building stones to also hold observational or ecological data. A very flexible module has been created to handle quantitative inventories. It has so far only been use by the Madidi project, but could easily be replicated and used for other projects. This module will be presented.

 

Investigating mechanisms of recurrent cyanogenesis cline formation in introduced populations of white clover (Trifolium repens)

Nicholas Kooyers and Ken Olsen (Washington University)


Lizards in an evolutionary tree: ecology and adaptive radiation of anoles

Jonathan Losos


Climate change, hydrology, and fish morphology: predictions using phenotype-environment associations

Matt J. Michel, Huichen Chien, Collin E. Beachum, Micah G. Bennett, Jason H. Knouft (Saint Louis University)

Because the environment exerts strong selective and inductive pressure on phenotypes, we often observe that certain phenotypes are associated with certain environmental variables among natural populations.  Here, we test for associations between fish morphology and flow rate for four species of stream fish and use these phenotype-environment relationships to predict future fish body shape and size in response to climate-altered flow.  We find that all species would need to undergo substantial changes to either body shape or size to attain phenotypes that would be adaptive to forecasted flow rates.

 

Disentangling regional, environmental, and spatial influences on beta-diversity in temperate and tropical forests

Jonathan A. Myers, Jonathan M. Chase, Iván Jiménez, Peter M. Jørgensen,  Alejandro Araujo, Narel Paniagua, Renate Seidel (Washington University)

 

Seeing the forest for the fungi: plant traits and decomposition rates
under changing climate

Brad Oberle (University of Missouri - St. Louis)
Wood traits influence both mortality and decay with important consequences for forest carbon balance during climate change.  We examine the impact of trait variation among woody species from Interior Highland Forests in long term experimental decay plots. After the first year of decomposition, stems lost 12-50% of their mass. While plot topographic position had a small significant effect, differences among species explained 56% of the variation in initial decay rates. These species differed in a suite of functional traits each of which explained relatively little variation in decay rates. However, a simple multivariate model explained almost as much variation in decay rates as species identity. On the whole, these results reinforce the effect of environment on decomposition and suggest an important role for combinations of wood traits that
distinguish different species.  Exactly how species’ differences influence saprophyte community structure and function during decay will be the subject of future studies.

 

Pathogens of Galapagos Birds

Patty Parker (University of Missouri - St. Louis)

UMSL Biology and the Saint Louis Zoo have collaborated on a survey of pathogens threatening the endemic avifauna of the Galapagos Islands.  We have used this foundation to build studies of the evolutionary ecology of host-parasite relationships using the tools of phylogenetics, phylogeography, and population genetics.  In addition, we have provided important management information to the Galapagos National Park, and they respond quickly with policy and action. 

 

Large scale latitudinal changes in herbivore pressure on two widely distributed neotropical Piper species

Diego Salazar (University of Missouri - St. Louis)

This is a test of the hypothesis that herbivore pressure increases along a latitudinal gradient towards the equator while controlling for host plant species.

 

Re-evaluating the relationship between geographic rarity and extinction probability." 

Kevin G. Smith, Karen R. Lips, Alison G. Boyer (Washington University)

   

The role of mid-domain effects on geographic gradients in biodiversity: Phylogenetic, functional, and phenetic perspectives

J. Sebastían Tello1,2,3, Richard D. Stevens2 and María Mercedes Gavilanez2 (Missouri Botanical Garden)

The most pervasive patterns in nature are geographic gradients of species diversity.  Focus is often on latitudinal gradients and numerous hypotheses have been proposed to explain why the number of species increases toward the equator.  A prominent, elegant and often-tested hypothesis is the mid-domain effect (MDE) that proposes that the random placement of species’ geographic ranges within bounded continents creates peaks in species richness at the equator and latitudinal decreases toward the poles.  Typically, this hypothesis is tested by estimating some measure of goodness of fit between empirical species richness and that generated from a simulation model.  Nonetheless, as has been recently pointed out, such curve fitting represents only weak tests of macroecological hypotheses.  One means of strengthening macroecological inference is to examine exchangeability.  The concept of exchangeability involves different yet simultaneous outcomes of the same mechanism. Two characteristics are exchangeable if they can both be expected given a particular mechanism.  Biodiversity is multifaceted, thereby providing numerous characteristics that can be considered exchangeable from the point of view of MDE.  Thus, independent tests of the MDE hypothesis can come from examination of goodness of fit of empirical gradients of other characteristics of biodiversity with those produced by a MDE simulation model.  We examined the degree to which a MDE model recapitulates geographic gradients in phylogenetic, functional and phenetic diversity of bats in the New World.  MDE models exhibited moderate fit to patterns of species richness but exhibited poor fit to most other characteristics of biodiversity. Significant deviations suggest that more than MDE determines geographic gradients in biodiversity.  Fuller understanding of gradients of biodiversity will come from simultaneous examination of random, environmental and historical mechanisms to better understand their relative effects on the distribution and abundance of the current biota.

1Center for Conservation and Sustainable Development, Missouri Botanical Garden, St. Louis MO

2Department of Biological Sciences, Louisiana State University, Baton Rouge LA

3Museo de Zoología, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador. Quito, Ecuador

 

Biotic resistance, niche opportunities, and the reorganization of an annual plant community by an exotic invader

Thomas J. Valone, Ginger R.H. Allington, and Michele R. Schutzenhofer (Saint Louis University)

Biotic resistance occurs when species interactions limit the invasion success of exotic species.  But the strength of biotic resistance is predicted to fluctuate, creating niche opportunities for invasion.  We test this prediction in an arid system. Native granivorous rodents suppressed the abundance of exotic annual Erodium cicutarium for 20 years on experimental plots.  But when rodent abundance declined, E. cicutarium escaped control, came to dominate the plant community, and negatively affected annual plant diversity.

 

Cave Speciation 

Li-Bing Zhang (Missouri Botanical Garden)

Species of karst caves have long fascinated evolutionary biologists and have been recognized as unique evolutionary models for studying natural selection and adaptation. Only a handful of species of cave flora have been described, while much more species of cave fauna have been recognized. Comparison of evolutionary patterns in different cave groups of organisms does not seem to reach any regularities. In the fern genus Polystichum (Dryopteridaceae), one of the largest genera of ferns with about 450 species,  the cave species have been placed using molecular data in younger lineages suggesting that they are new endemics. Most notably, several morphologically and palynologically different cave species of Polystichum, occurring geographically in adjacent areas, formed a well-supported monophyletic polytomy, implying an unresolvable hard polytomy.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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